The core activity of “intercepting communications” described in section 8 was designed to be technology-neutral while defining the Bureau’s unique signals intelligence role within New Zealand’s intelligence community. But “intercept” and “communication” are defined so broadly in the Act that they can be read in such a way as to capture activities which do not involve interception in any ordinary sense of the word – such as exchanging foreign intelligence reporting or even imagery data with an overseas partner. This lack of clarity has created uncertainty and therefore risk for the Bureau in undertaking core business.
[Emphasis added]
To see what they're complaining about, let's go to the definitions. A "communication" is just that. But
intercept includes hear, listen to, record, monitor, acquire, or receive a communication, or acquire its substance, meaning, or sense
Which clearly covers not just directly listening in to and recording communications, but also receiving them or receiving summaries of them from other agencies.
This shouldn't actually be a problem if the GCSB stuck to what it was authorised to do by Parliament - spying on foreigners. It is only a problem if they are receiving copies or summaries of the communications of New Zealanders from their foreign partners - that is, if they are using those partners to circumvent the law against spying on New Zealanders. People have long suspected GCSB (along with GCHQ and NSA) does such "swapsies" to circumvent local bans - and GCSB appear to have just admitted it to Cabinet.
The new spy law would legalise that practice (as well as enable GCSB to directly spy on kiwis on a massive scale "allow the GCSB to see who (namely New Zealand individuals and companies) is being attacked"). We cannot let them do this. Instead, this agency has become an active threat to New Zealand's democracy. They need to be defunded and shut down.